


Adult

by Adventuresofdeadyamcha



Category: Star vs. The Forces Of Evil
Genre: Aged-Up Character(s), Coming of Age, Established Relationship, F/M, First Time, Post-Canon, Slow Burn, starco
Language: English
Status: Completed
Published: 2018-04-26
Updated: 2018-04-26
Packaged: 2019-04-28 01:44:45
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 8,745
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14438823
Author URL: https://archiveofourown.org/users/Adventuresofdeadyamcha/pseuds/Adventuresofdeadyamcha
Summary: Star and Marco deal with the looming responsibility of ruling a kingdom, their strong desire for each other, and coming to terms with growing up.





	Adult

**Author's Note:**

> I wrote this self-indulgent piece while recovering from breast cancer. Got a little carried away with word count, but here we are, I guess :p

There is something mystifying about a crowded room—an intimacy when body meets body without intent or concern, swirling and grinding to a thundering bass vibrating the wood beneath their feet. Ever-changing neon lights flash sporadically, illuminating a sliver of a face, a mold of an individual among a hive of featureless throbbing bodies. The air is thick and sticky, fresh oxygen minimal although unnecessary as dancers inhale one another’s hot breath. Voices are faint, silently screaming prose in perfect unison. The entire atmosphere is intoxicating and feels like nothing else on Earth ever has.

Which is probably why Star forgets that she’s back on Earth. She feels like she is surrounded by aliens, but the feeling isn’t one of fear or alarm—instead she is flooded with ecstasy as she jumps in tandem with the crowd, her hand inches from tapping the low ceiling of the Diaz’s basement. Right before her feet reach the floor, she lurches forward, pushed by a teenager behind her. She forgoes all attempts to steady herself, allowing her body to collapse in her boyfriend’s arms, laughing a candy-coated laugh as Marco collects her, clearly more concerned with her wellbeing than she is. He’s saying something to her, but his words are lost in the music, and she can only smile under long lashes painted vibrant hues from the party lights. She finds his mouth desperately, pressing herself to him in tune with the beat. He accepts her affection before breaking the kiss and lowering his mouth to her ear.

“Star, let’s take a break,” he probably yells, but his words are muffled and hollow against the rage of the party.

She nods in agreement as Marco takes her hand, pausing to search for the best path to exit the throng of teenagers. But Star isn’t the type to hesitate, yanking his arm as she navigates the crowd effortlessly, making momentary stops to kiss Jackie on the cheek, or hip-bump Kelly playfully out of her way, or twirl herself under Marco’s hand to break up Tom and Janna dancing closely, winking at them as she passes. She is a force to be reckoned with, so Marco follows obediently, through the crowd and to the back of the basement, stuffing himself into the small bathroom after her. He flicks the light on, and they both take a much needed sigh of relief.

The bathroom is cozy, to say the least, but it is much quieter than the rest of the basement, the heavy door separating them and their friends enough to drown out most of the sound. Star is already pressed against the tiny sink, her face as close to the mirror as she can get, fixing an invisible imperfection on her lipstick line.

“Are you ok? Brittney hit you pretty hard,” Marco snorts irritably, “That definitely wasn’t unintentional either. She’s so aggressive! I have every right to kick her out for that, ya know.”

“I’m _fiiiiine_ ,” she drags the word lazily, waving her hand, “it was an accident. Not like there’s a whole lot of personal space out there anyway!”

“I suppose. I just don’t want anyone getting too rowdy and turning my parents’ basement into a total pit. If they came home and saw a big mess, they’d kill me!” He pauses then deadpans, “They’d kill me and replace me with my brother. No one would ever even realize.”

Star giggles that maple-sweet titter of hers and his heart clenches. His thoughts are then pulled from his brain one by one as she tosses her hair over her shoulder, combing her fingers through it carelessly. Her back is bare besides the thin yellow straps holding her tank top up, beads of sweat glittering across her small purple wings. He watches the reflection of her collar bone rise and fall as she huffs, impatiently pulling at a sticky knot of hair. He holds his breath.

“Oh _Marco, Marco, Marco_. Have I told you lately that you worry too mu—“ Words drop from her mouth at his touch on her back, his hand palm-down between her shoulder blades and wings, his thumb caressing her skin softly. Her eyes meet his through the reflection of the mirror and she grips the sink hard.

“You have a bruise,” His voice barely squeaks, the sudden tension in the tiny washroom suffocating him.

Star’s face remains impassive as she spins her body around to face him, the closeness of their bodies suddenly realized. Never breaking his gaze, her hand reaches for the door in what feels like slow motion, pressing the lock down with her thumb. The click and snap of their privacy seems to echo off the walls as a distinct tightness coils in Marco’s gut, a fire burns through Star’s eyes, a subtle pink glows over her heart-shaped cheeks. The intensity between them crackles and fizzes until it finally bursts in one swift motion as Star latches her mouth to his. He embraces her hungrily, not realizing when he lifts her onto the sink, his hands wandering her back and bottom aimlessly.

Her head is spinning, heat boiling low in her abdomen as she squirms into him, feeling just how tense he is. She slips a hand in the back of his jeans, sliding around to the front of his waist band as he bucks against her delicate touch. He parts from her, panting helplessly as he buries his head in her neck, kissing and sucking every inch of skin he can reach. Star meticulously plays with the button on his jeans until a flick of her forefinger unfastens it, warranting a gasp from him against her shoulder. He squeezes her thigh, hand working higher and higher up her skirt toward the hottest part of her. She’s putty in his hands at this point, limp and useless as he wanders into virtually unknown territory. But Star is Star and can’t be outdone, forcing her tingling hands to stay busy with his zipper, pulling weakly at his jeans and praying they just _know_ to tumble to the ground. But before his hand reaches her, and before she manages to wiggle his pants off his hips, he stops.

“Are— _are you ok_?” He exhales, his voice a whisper. She can feel his arms shake under the weight of their situation.

“Now’s not the time to be the safe kid, Marco,” she sing-songs, voice high-pitched and breathy.

He chuckles low, leaning his forehead against hers, “I love you, Star.”

“I love you, too,” she coos, turning her head to kiss him chastely, but only for a moment because Star is hungry, her mouth pleading with his to pick up where they left off. He puts his hands under her bottom, lifting her up to pull her even closer, the quickness of it all enough for her to expertly finagle his cursed jeans off of him. Denim crumbles to the floor, and her heart drums wildly in her ears.

“What are we— _here_?” He gasps between kisses, his fingers now fully up her skirt, pulling down the sides of her underwear, his voice much more unsure sounding than his hands.

“Yep.” Is all she can muster as she locks her legs around him, using the momentum to work his boxers down with her calves as he pins her to the bathroom mirror. She never guessed their first time would be smashed in the Diaz’s basement bathroom, but she was ready on all fronts to get this thing _going_.

“Hey Staaaaaaar, are you in there, girl? It’s been like twenty minutes and I really gotta make sure my make up is PER-FECT, ON-POINT, like, STUN-NING, ya know what I’m saying?” Pony Head’s shrill voice cuts through their panting, barely registering to the hot and heavy pair.

Marco and Star freeze, eyes wide—deer in headlights, hearts stampeding against their rib cages. Marco waits for his girlfriend to respond, nudging her with his arm encouragingly.

“Uhhhhh yeah, I’m in here,” she wheezes like a balloon releasing air, her and Marco finally putting some distance between one another and quickly adjusting their clothing, “I’ll be out in a second.”

Star widens her eyes at Marco, pointing frantically at the door, unsure how they can leave at the same time without anyone knowing what just almost went down.

Marco smirks, crossing his arms over his chest, “Now’s not the time to be the safe kid, Star,” he taunts, gesturing for her to lead the way.

She can’t help but laugh, rolling her eyes and kissing his cheek before opening the door, the heat and noise of the party overwhelming their senses.

Pony Head watches them both exit, half gasping, half cackling maniacally, “REALLY STAR, you and Earth-turd couldn’t wait until after the party?! And for twenty minutes?! Oooh girl, you gotta get CONTROL of your mans!”

Star walks past her friend chin forward, Marco following closely behind her, both trying to stifle their laughs. They return to the party as normal as possible, but something intense awakens inside them.

The next time it almost happens, a week has passed since the Diaz’s infamous mid-senior-year bash. They didn’t speak of their bathroom rendezvous, but things didn’t quite return to normal either. The focus shifted in their texts and calls—their loving, romantic relationship turned starved, undertones of their hormone-addled brains craving physical touch beyond snuggles and kisses not unnoticed. They know they opened the flood gates to some dangerous territory, but they had gone too far to turn back now.

If only they had the guts to actually talk about it.

In the meantime, Star returns to Mewni, well aware of the vicious creature that now lurks in her gut, her lust uncontrollable and tearing through her better judgement like Meteora tore through her kingdom years ago. She sits in lessons with Glossaryk and her mother, her only reprieve from her hormones being the knowledge that she can’t see her boyfriend until the weekend; for once, she’s grateful that their dimensions keep them apart during the week. She tries to focus her attention on her studies, but her mother’s voice can’t hold her concentration like her own imagination can.

“Star, pay attention!” Moon commands, jolting Star up in her chair as she removes her wand from her mouth after mindlessly chewing on it.

“I’m listening!” She claims, but she knows Queen Moon is no fool—her attempts are futile as her mother can see right through her.

“Now is not the time to be worrying about boys, my dear. Your transition to the throne begins in just over a year and then you officially become Queen on your twentieth birthday. I know that seems far away, but I assure you that the years move faster than you anticipate,” Moon recites her advice, noticing as Star’s eyes glaze over once more, so she adds for good measure, “Most queens marry within their first year of ruling, you know.”

Star scoffs, rolling her eyes outlandishly, “Mom, you know Earth customs are different. 20 is hardly adult enough to get married!”

“I was married by 18, it isn’t something to drag out. I ruled the kingdom myself for 3 years and it was extremely challenging. You don’t have the time or resources to be so emotional about it all—your King is your partner in reigning over your people. You pick them based on skills and not on fleeting teenage hormones,” the Queen pauses thoughtfully, “Although, I think Marco is an excellent choice for King. But that’s because of his skills as a leader, not his romantic chemistry with you.”

“ _Ugh_ , ok mom, lets get back to the lesson, “ Star huffs, uncomfortable with the turn the conversation has taken.

Unfortunately, Moon’s advice falls on deaf ears, overall making Star sweat more, her uncontrolled urges louder than before—she imagines having him as her King and getting to have her way with him whenever she pleases, _however_ she pleases. She often talks with Marco about returning to Mewni as her knight (King-in-training) once he graduates, but suddenly the thought of living together again haunts her, causing either sleepless nights or wakeful dreams ending in only sexual frustration and extra laundry work for Sir Lavabo. For the first time in her life, she’s dreading the weekend.

However, Father Time—that unreliable flake—decides to keep on his wheel causing Friday to come quicker than Star can stand. The weekend routine is the same as it has been for hundreds of times during their four year friendship; an old Mackie Hand film croons on the tv while Star and Marco sit intertwined on her bed surrounded by snacks and soda. Star sits in between his legs, her back leaning against his chest; she can feel his throat rumble against the crook of her shoulder when he laughs at the same point in the movie he always laughs at, his arms squeezing around her instinctively. The scene should play out like it always does—with laughter and cuddles—but as his breath tickles her ear and his body tightens around hers, Star isn’t laughing. She feels a rumbling, twisting pang dwelling in the pits of her torso, bubbling and boiling until it explodes up her chest, burning on her face like the sun. She prays he can’t feel her cheeks radiating, prays he can’t feel her heart galloping, prays to any magic being in the universe for a distraction so she doesn’t turn around and tear his clothes to shreds.

But Star Butterfly has never been particularly lucky, and she can’t keep her hands to herself much longer, twitching against the sheets beneath her. Even her episode through Mewberty couldn’t compare to the unbridled, uncontrolled fire ignited in her gut, burning wild with no hopes of being stomped out. She fights with herself internally for what feels like centuries, desperate to follow the demands of her new abdomen-dwelling friend, but attempting to channel all forces of the universe to keep herself under control anyway; but _goddammit_ , Marco is wonderful _but has shitty timing_ , burying his face in her neck, kissing softly and holding her close and she almost splits open dimensions like a pair of sentient scissors.

“Urghhhhhhh, _Marco_!” She snarls like some violent animal, something hot and akin to rage coasting through her as she flips around, pinning her unprepared boyfriend beneath her, “You, you, you....”

Marco’s eyes bulge, gripping her wrists just to have something to keep him anchored to the bed (and to reality), “Star? Are you ok?!”

Her words fall from her mouth and she realizes she has nothing to say that wouldn’t horrify her, a new feeling of embarrassment blooming in her chest as she decides to keep her words to herself.

“I want to have sex,” she still hears herself say out loud, her godforsaken mouth betraying her as always.

“W-with me?!” Marco blurts, nearly equally as embarrassing given the obviousness of Star’s blunt statement. He is her boyfriend, _of-course-she-meant-with-you-Diaz._

Their exchange happens so quickly that when they realize how ridiculous they sound, Star sighs, collapsing next to him, dragging her hands down her face.

“I have no clue why I just said that,” she groans, “I’m sorry, Marco, I didn’t mean to attack you. I don’t know what’s wrong with me. I feel like I’m about to explode all the time and my brain—or my _something_ —isn’t connecting to the rest of me and my guts feel like boiling lava. Y’know what I mean?”

She peeks behind her hands when she hears him chuckle, watching as he readjusts, propping his head on his elbow as he lays on his side facing her.

“I know the feeling, I really do. It’s gotten so bad that my own mother knocks on the wall before coming into any room I’m in cause I just can’t.... _get a grip_ , if you catch my drift,” he admits, wincing at his own confession.

Star mimics his position, turning to face him, a half grin slung on her face, “You think that’s bad, you should see what Lavabo has to deal with! My dreams have been so vivid that my laundry piles up every time I even blink for too long.”

A genuine belly laugh bellows from Marco, contagious and sweet, causing Star to echo fits of giggles. Their hysterics come to a slow, concentrated stop, eyes locking, smiles heavy under the weight of affection the two carry for one another. Star closes the gap between them, gently pushing him on his back, half her body hovering over his as she dips down for a kiss, her pelvis-demon quieted while her heart reigns over her feelings momentarily.

The moment is fleeting though since _goddamn Marco Diaz_ pulls her on top of him completely, deepening their kiss as Star’s breath collapses from her lungs. She gets forceful fast, greedily lapping up her lover like a starving street cat, twisting and pushing her lower half into his, intensity rising further when she sits up to remove her shirt. She discards it dramatically to her side, but her theatrics go unnoticed as Marco’s eyes are captivated by her nakedness. He has seen her in swim suits before, and obviously they have had some make out sessions that included heavy petting, but never has he seen her like this: tight stomach panting, dreamy eyes lidded, perky chest cupped in pink lace. It’s enough to make him erupt right then and there and Star knows it, feeling him shudder beneath her. She pushes her hands delicately under his shirt, fingers tracing up to his chest, preparing to tear his T-shirt into oblivion if it means it would no longer be a hindrance to his body. The truth is that Star already knows every crease of his body, could paint a perfect picture of his still-emerging abs, could create a map of the constellations connecting every freckle and mole from memory—but knowing and feeling were two different things and she begged her fingers to commit every soft touch to her cognizance, tucking away every quiver and shake he released into the corner of her mind for future reference.

She was too lost in her thoughts to realize her hands did the work for her, banishing his shirt into the pile of clothes next to them. Now it’s her turn to stare—her sweet Marco, vulnerable and beautiful and loving and _beneath her_. She salivates, swallowing her excess spit hard, not wanting to wait even a single second longer to feel skin on skin, but she’s mesmerized. She stares down at her boyfriend triumphantly, feeling like queen of the castle until he flips the script suddenly, his hand cradling her neck down to him, crushing their lips together while twisting her back to the bed. She isn’t sure how, but he’s on top of her, her insides practically exploding. His fingers are cold compared to the sweat of the rest of him as they dance along her body, sending shivers through her chest, goose bumps prickling at her arms. Every move he makes is deliberate, from the kisses he leaves along her chest, to the press of his lower half into hers, to his fingers brushing delicately against her throat while the other hand secures his place above her. She mewls at his touch, surprised at his fluidity but won’t look a gift horse in the mouth, instead counting her lucky stars to be so in love with this man— _her Marco._

She forgets that her luck only goes so far.

A crash and clink from outside her balcony door shoots them from their haze, both scrambling intuitively under the covers to keep some semblance of decency between them and whoever was brave enough to show up at her door unannounced (and _absolutely_ uninvited). They laid side by side, breathing labored, sweat beaded along their foreheads, clothes scattered around them.

“Hey Star, is Marco over? I have some questions about Janna and I might need you two to do some low key reconnaissance for me,” Tom’s voice cuts through the door before he can, jiggling at the handle forcefully, “ _Goddammit_ , why is this thing so hard to open?” he barks, and Star begins the count down before he gives up and blows the door open all-together, knowing their feisty best friend to know no obstacle nor, apparently, privacy.

Luckily, her sweet Marco, her safe, dependable, wonderful Marco, thinks faster than she does, launching from the sheets with a grunt to retrieve their clothes, her shirt suddenly whipping her in the face like a blast of magic. Before she realizes it, Marco is next to her, above the sheets, hugging a pillow to his gut, gnashing his teeth together in anticipation. Star follows his lead, her shirt back on her body in time to brace herself from the inevitable explosion from the balcony that follows.

Tom steps in through the rubble and smoke, waving a hand around to search for his friends among the destruction. The fog dissipates to reveal Marco, hiding half of himself behind a throw pillow, and Star lounging on her back, head hanging off the bed, eyes on the rolling credits of the Mackie Hand movie.

“Really? You guys were just gonna ignore me like that?” Tom pouts, hands on his hips and a growl beneath his smart-ass remarks.

“Can’t you see we’re watching a movie here?” Marco gestures open-palm to the black screen, the credits now finished. Tom cocks his head and furrows his brow, knowing they’re hiding something, but he can’t quite place what it could possibly be. He’s skeptical of the situation, the three friends being so virtually inseparable that it’s strange they would keep a secret from him.

“Besides, it’s so much fun to tease you, you know that!” Star pipes up, finally catching her breath enough to form coherent sentences.

Tom squints and looks around the room, trying to put the pieces of this puzzle together, making mental note of their disheveled hair, the twisted sheets, the heavy breathing, Star’s shirt completely inside out, the snacks scattered along the floor.

Wait, inside out?

Reality hits him like a truck, his lips curling under, nose scrunching in horror, “Oh no, oh my god, I interrupted you guys,” he declares in panic, holding his head and pacing, a small trail of flames following with every step, “I am the worst bestie in this dimension, I can’t believe I didn’t think you two might be uh....” he gulps, “.... _busy_? Oh my god I’m the worst.”

Star is the first to leap to his side, “No, no no, Tom, you’re not the worst bestie, not even close,” she assures, “but, have you ever considered calling first?”

Tom can’t answer, as Star is way too close and her shirt is way too inside out and her neck is way too red and he looks to Marco for some sanity, but Marco is pink-faced and cowering behind a pillow and Tom realizes what he’s trying to conceal and _oh-my-god-he-is-such-a-dingus._

“Wow, Star, Marco, I love you both dearly, but I’m gonna go ahead and leave and pretend like this never happened,” he rushes for the hole where the balcony door once stood.

“You don’t have to go, it’s _fine_ , Tom!” Star tries, but he is already too traumatized—not by his imagining of the types of things they do behind closed doors because _hey_ those are his friends and that’s what couples do—but by how absolutely dense he can be sometimes. He hopes they never mention this to Janna.

He hopes they never mention it _period_.

As he disappears into the sky, Star snatches her wand from the ground, mumbling a colorful spell that repairs the wreckage instantly. She stands still for a blink, her worry turning to frustration as she groans, tossing herself back on the bed and burying herself in a pillow.

“Seriously, it’s like the universe doesn’t ship us or something,” she whines into the fabric, turning slightly to check on the status of her boyfriend. She raises an eyebrow when she notices his joints locked, clinging to her rainbow pillow for dear life, “Marco? Are you ok?”

He turns his glowing pink face toward her, “I can’t leave this pillow right now.”

She’s a bit confused, moving closer to see what he is talking about, but he pulls away abruptly, squeezing his shield closer to him.

“Star, you don’t understand, my pants...” he sighs ashamedly, “my pants need.....a trip to the Knights of the Wash.”

“Huh.” Star blinks, suddenly very aware of her own uncomfortable moisture in her skirt, “Welp, same here, Diaz.”

Marco relaxes slightly at her confession, still refusing to release the pillow. She smiles at him, pulling herself to her knees and crawling to sit in front of him, eyes dizzy and hair wild. She cups his cheeks in her hands and pulls his warm face to hers, kissing him deeply.

“Take your pants off, Marco.” She commands against his mouth.

He tenses up again, but there’s sugar to her demand as he scans her eyes—playful and impish and the most beautiful shade of blue—and he catches the joke before she can get to the punchline.

“S-so we can take them to the wash?” He quietly curses the way his voice sometimes cracks when he’s nervous.

She nods, “So we can take them to the wash.”

He relaxes again, smiling sweetly and finally letting go of his pillow shield, pecking her quickly on the lips, “Then we go find Tom?”

Her smile widens and she kisses her boyfriend back again, “And then we go find Tom.”

She takes his hand in hers, planting her lips in his palm, then switching them out for his dimensional scissors, “I’ll freshen up in my bathroom, you go to yours and we’ll meet back here in 15.”

She hops up from her seat and skips to her bathroom, giving him a bit of privacy. He watches her wink as she shuts the door behind her and he swells with gratitude that he found her, his inter-dimensional-alien-girlfriend, spontaneous and beautiful and strangely mature when she needs to be. He uses the scissors and hops dimensions quickly, hoping after their adventure with Tom is under wraps, they can finally get some time alone.

They meet back up—fresh and stripped of any evidence of their previous entanglement—and rush to find Tom in the Underworld. After some coaxing and considerate reassurance, the three friends go off on what feels to Marco like the longest, most tedious adventure of his life. Star always loves to play matchmaker, especially with Tom, blaming herself slightly for the half demon’s serial-dating and perpetual singleness. Marco knows better though, knows that Tom is just Tom and he truthfully enjoys playing the field. But this time, Tom and Janna started dating quietly without the meddling of their mutual Mewman friend and Star can’t stand that it wasn’t her idea. So she pokes and prods and delves further, never able to satisfy her incomprehensible curiosity. Her obsession to make her friends happy seems to be a tremendous distraction though, Marco noticing she can touch him again without blush, their physical closeness back to being more platonic than that of lovers in heat. He wishes he could change focus as easily, his mind still savoring the image of her topless, eyes feral, hair untamed, the weight of the future Queen of Mewni on his lap burning in his memory. He mentally kicks himself, trying to focus on not falling out of the tree they set up camp in, watching over Tom and Janna like a couple of perverts. He hopes for an opportunity to return to the castle, but spying inevitably turns into joining the new couple at the arcade, which leads to running into Pony Head and her fling-of-the-month, which leads to an early evening at their new favorite club on Mewni. For once, Marco wishes dimension hopping wasn’t so easily accessible, pleading for their adventure to simply lead them home.

Luck isn’t on his side, either.

Finally, after an arduous day of pretending like he isn’t imagining his girlfriend naked at every chance, the two head back to the castle to clean up. His hopes are dashed once again though, as Queen Moon corrals her daughter in a pit of fabric and measuring tape as soon as they arrive home, insisting she gets fitted for her upcoming eighteenth birthday, spewing some nonsense about how a Queen must age gracefully. His eyes nearly roll out of his head, finally giving up waiting on her and retiring to his room down the hall. None of the day had gone to plan and he was ready to sleep and start over in the morning.

Suddenly his disposition shifts, realizing that he doesn’t have to wait until morning—the only time when Star is completely alone is in the dark of night—a plan formulates in his brain. He sets an alarm for 11pm, and allows himself to drift into a restless, uncomfortable doze.

When he awakes, he springs from his bed, slithering soundlessly down the hall, palming the stone wall to guide him through the darkness of the castle. He opens her door with trepidation, gliding into her room on the balls of his feet, not wanting to startle her into Narwhal-blasting him into oblivion. He hovers over her bed, releasing his breath before sliding under her sheets and snuggling up to her, Star only stirring slightly before falling into step with their comfort. It certainly wasn’t his first time sneaking around the castle to sleep with her, but it felt different now, knowing it wouldn’t stop at cuddling. He prepares to wake her up, barely able to focus on anything but her slightly parted lips, her chest rising and falling, eyes twitching behind her lids. He takes a few deep, frayed breaths and decides to just dive in.

Marco plants a kiss on her mouth, only taking a few seconds before she is aware of his presence. He tries to pull away to give her some space to wake up fully, but he finds his kiss has roots, her hand suddenly fisted in his hair as lips press and teeth clash in the wake of passion. He’s overwhelmed by her momentarily, never having made a plan for when he actually got this far and realizing the chance of an interruption was slim, the implications of being completely and utterly alone making him feel like he’s drowning.

Star must also realize that they are finally, truly alone, wasting no time in unbuttoning his pajama shirt and yanking it greedily off of his shoulders. He lets her do the work for him, temporarily frozen, his lips working hers on instinct alone. He’s distracted by her hands pushing down the elastic of his pants, using her thighs and feet to wiggle them to his ankles where he kicks them off intuitively. He draws a blank, still a nervous wreck, but luckily Star knows he sometimes needs a push, breaking their kiss to hike up her sleep dress. She wriggles and squirms until it’s over her head and onto the floor and in that second it occurs to Marco that there is no underwear this time. He’s suddenly marble, unmovable and panicked and sinking into himself, his insecurities dropping in his gut like an anchor. She’s the future Queen of Mewni, she’s bright and beautiful and helplessly optimistic and spread out beneath him and he just knows he doesn’t deserve her, doesn’t deserve _this_ , and for once he worries he is in way over his head.

He’s pulled from his self-loathing when her knee pushes him gently in the stomach, Star sitting up and catching his face in her hand. She’s looking at him like he’s completely transparent and he’s humiliated that he’s ruined the moment, unable to match her eye contact.

“Hey, look at me,” She nudges his chin, guiding his glance to catch hers. She smiles at him dopily, eyes heavy with affection and he feels his heart swell, “we don’t have to do anything you don’t want to. I’ve got you, Marco Diaz, ok? And I love you. No matter what.”

He feels a build up of pressure behind his eyes, choking on any words that might come out. He finally cracks a smile, cupping her cheeks in his hands and brushing his thumb along her hearts.

“Let’s not pretend this was your idea, Star,” he jokes, pressing his forehead to hers. She releases a light flutter of a giggle, pulling him into a hug.

The skin to skin contact renews his fervor, pushing her back down to the mattress assertively. She blinks hard, unsure if she’s reading him right, but his smile is confident—she thinks to herself that he looks like a King—and suddenly his mouth is on the pulse point on her neck and words have never failed her more spectacularly.

A bright orange light radiates behind Marco’s head and she notes how ethereal and otherworldly he looks. But it kicks in quickly that the light isn’t supposed to be there, and Star sighs, garnering the attention of Marco, who turns his head to see what could possibly be distracting them this time. He recognizes the distinct orange dimensional portal, bright and blaring and _interrupting again_.

“Is that Hekapoo’s portal? Marco, are you still moonlighting as Hekapoo’s sidekick?!” Star accuses, trying not to sound upset at the idea.

“No, I swear, I haven’t done that in years,” he admits, “she must really need help if she’s coming to me. I’m sorry, Star, I should probably go see what she wants.”

Star stands up after him, tossing her sleep dress on while Marco clothes himself, “Well, I might as well go with you. Maybe with two of us we can get the job done twice as fast.”

Marco smiles, gesturing for his girlfriend to enter the portal first, Star skipping in without hesitation.

As it turns out, Hekapoo was indeed in need of Marco’s specific assistance; a portal he opened years ago remained open and, due to it being unattended for so long, it required his scissors to close it for good. He thinks this should be a fairly easy mission and he and Star can be back in bed before dawn. Unfortunately, tracking the portal down proves to be more difficult than he previously thought, taking the trio hours before they are finally face to face with his electric blue portal, spinning wildly in front of their eyes. With a slip of his scissors, the portal zips shut, disappearing for good. Marco turns to his teammates, taking a moment to glance around the dimension.

“I’m surprised this is where I would leave a portal open,” Marco muses aloud, “I figured it would be in Hekapoo’s dimension since I always loved it there. It was fun being such a cool adult.”

“Marco, not to be weird, but you sure look like an adult to me,” Hekapoo playfully jabs him with her elbow, “In fact, I’d say you look more like you now than you ever did in our sixteen years of running around.”

Marco smiles down at Hekapoo—who was now Chancellor of the Magic High Commission—grateful for the friendship he formed with the powerful ally.

“I also think our Queen has passed out,” the fire goddess chuckles, a finger extended toward Star curled up in a ball on the red sands below their feet.

“Only she could fall asleep at a place like this,” Marco laughs, “I better take her home. Thank you for everything, Hekapoo.”

He slips his arms under the princess, cradling her as he lifts her toward the portal. Just as he has one leg in another dimension, he hears Hekapoo’s voice once again, ringing clearly and confidently in his ears.

“I look forward to working with you as King, Marco!”

He steps back into Star’s room, his face overheated from the unexpected comment. He never thought of himself as King— _that is_ , he knew it would probably happen but not for many many years. It hadn’t hit him prior that he and Star were growing up, their life about to become much more complicated.

He gently lays her on the bed, watching her sleep soundly, and he thinks that he’s ready for any complications as long as he has her by his side. He slides into bed next to her, holding her closely as he drifts into a deep, cozy sleep.

He awakens to sunshine gleaming, his face full of golden hair, limbs tangled with his princess. He inhales her scent—sweet and nutty with a hint of must from sweat—and tugs her closer to him, his face burying in her chest, trying his best to eliminate any space left between them. Star twirls a lazy finger around the hair at the nape of his neck, propping her head on his. They are comfortable, as they have always been with each other, their bodies fitting together like a puzzle. Star begs the universe to stay like this forever. But life has other plans for her as a sudden but slight temperature drop trickles on her face, the warmth of the sun gone. She stirs, groaning and frustrated as she peels her eyelids open to reveal a mysterious figure standing near them—tall, with a large heart shape at the top, a crinkled nose prominent between two diamond cheeks.

_Oh gods, it’s her mother._

Star sits up in a tizzy, knocking Marco off of her and straight into reality, his eyes flying open and instinctively covering his top half with the blankets.

“Mom!” “Queen Moon!” They gasp in panic.

Moon’s face twists, taking a step back to curtsy, bowing her head slightly, “Queen Star, King Marco, how gracious of you to awake at a quarter past one! I just wanted to let you know the staff has not yet been fed—the menu needs a few adjustments—and you’ve missed three meetings with a few of the townspeople, and Sir Lexington requires your immediate assistance in assigning him a new squire as his has taken position in the castle elsewhere. He claims he needs the job filled by 3pm, but I’m sure you can push that off, too!” Moon grins, her gestures exaggerated, her voice syrupy sweet and thick with sarcasm.

“W-what, I didn’t realize, I didn’t know— _that is_ I wasn’t aware....” Star sputters, Marco still hiding uselessly behind the blankets, too startled to move.

“Lucky for you, _I_ was awake at the appropriate time for royalty and was able to complete the tasks before 11,” Moon pinches the bridge of her nose, “Star, you know you have duties to attend to daily as Queen and these are just the minuscule responsibilities I delegated to you! You are inheriting the entire throne in just over a year and I don’t want you to be unprepared or overwhelmed.”

Star sighs, hanging her head low, “I know, I’m sorry, mom.”

Moon’s expression softens, “Let’s go through a few tasks this afternoon after I get back from my trip with Buff Frog. Please understand, I know how it feels to be handed a kingdom you aren’t ready to rule—you don’t want to experience it. You have this time to prepare, you should make the most of it,” she glances away from her daughter to look Marco up and down, “Marco dear, you need to be re-fitted for your suit so please see the tailor before you leave Mewni. Do you both understand?”

The teens nod wordlessly.

“Good. I’ll leave you be now.” She stalks out of the room, shutting the door carefully behind her.

Star exhales the breath she is holding and covers her face in her hands, a low groan humming from her throat.

“She—she....didn’t care I was in here?” Marco finally mumbles, hands still fisted around the covers.

Star peeks at him, an amused smile tugging at her lips, “ _That’s_ what you’re worried about? Oh Marco Diaz, you beautiful dum dum,” she wraps her arms around his shoulders, pinning his arms to his side, “This isn’t Earth—Mewni just isn’t as strange about affection as you guys are. Especially between two adults.”

Marco kisses the top of her head, mumbling into it, “Are we really considered adults now, Star?”

“Heh, I guess so,” she shrugs into him, “I don’t always feel that way when we go on adventures like last night. I feel like I’m fourteen all over again.”

“Fourteen and in loooOoOve with me?” He teases, poking her cheek with his index finger.

She swats at his hand, “Yeah, yeah I get it. At least I _knew_ I was totally helpless for you. Took me literally leaving Earth for Dr. Smarty-Pants, PhD to figure it out.”

He catches her second swat and brings her hand to his lips, “Dr. Smarty-Pants, PhD?”

“You know—pretty handsome dude,” she deadpans, the two of them bursting into giggles, Marco wrapping his arms around her and squeezing her tightly.

“We should get going before your mom comes back.” He coos, brushing her hair delicately with his fingers.

“I know. But one more minute won’t hurt.”

They hold each other closely, a calm rushing over them, one minute lasting only a blink of an eye.

After they reluctantly part ways, Star dresses and gallops through the halls, her mother’s words from the prior week tugging at her brain. She can’t stop thinking of Marco as her partner in ruling and not just as the man she desperately wants spread out beneath her. She wonders if there is really a separation like her mom claims because she can’t imagine loving someone without _physically_ loving them.

A lot has happened to them the past few days, and the tension build up between them is reaching its climax—would they still be ok after they go to the next level? She worries Marco isn’t there yet and for one, terrifying moment wonders if he’ll ever be ready—ready for sex, ready for the crown, ready to be with her fully and wholly. But Marco is secure in their relationship, never making a decision without doing research, and he has never been one to leap head first into action without thinking. Maybe Star _isn’t_ worried about Marco at all—maybe she’s projecting her own fears on him, and maybe _she’s_ the one who isn’t ready for it all. Her thoughts come to a screeching halt when she suddenly finds herself in her mother’s room, Queen Moon sitting at her vanity, her fingers deftly working at her hair.

“Star? Did you need something?”

“Mom, how did you know you were ready?” Star asks point blank.

“Oh darling, I told you I was never ready to be Queen,” Moon responds nonchalantly.

“No, mom....not Queen. _Ready_ ready. Like, ready.....with, uh.... _dad_ ,” Star says.

Moon blanches, stumbling over her words, clearly caught off guard and embarrassed, but she composes herself quickly.

“ _Oh_. Well.....he braided my hair.”

“He _what_?”

“Braided my hair. I know it sound ridiculous, but I was going on a low key scouting in the Forest of Certain Death and grousing about my hair being too long for these missions. Your father asked why I didn’t simply cut it and I explained that _clearly_ it was proper for a Queen to have long, beautiful hair. He didn’t seem to understand, but instead of trying to reason with me, he sat next to me on my bed and asked if he could try something with it himself. I said yes, and he braided it, and it was....a small but very significant act. Something so intimate yet thoughtful yet reasonable and I realized then that this was the man I needed at my side. We were 17 then, and he braided my hair for me for years. Sometimes he still does.”

Star stares at her mom, starry-eyed and mystified, the answers to her questions laid out bare before her, “Mom, that is the most romantic thing I’ve ever heard in my life. Sounds like you thought about romance a lot while you ruled solo, huh?”

She hesitates, “I suppose you’re right, Star. Maybe I exaggerated when I told you that it shouldn’t be a focus,” she breathes, “because River is a huge part of my success as Queen and my success in raising an incredibly capable future Queen.”

“So.... _do_ you think I’m, um, ready?” Star wrings her fingers together nervously.

“I think you’re ready to make decisions for yourself. Smart ones, I hope! _Safe ones,_ too! Possibly where I never have to know about them,” Moon politely chuckles into the back of her hand, “but yes, Star. You are an adult and nearly the Queen of Mewni. Whatever you decide is best for you, _is_ probably best.”

Star launches at her mom, hugging her tightly. Moon is a bit surprised, but returns the affection, silently choking back tears because it’s not becoming of a queen to cry.

“Thank you, mom. I’m so happy to have you. You’ve cleared everything up,” and with that, Star is out the door and gone. Moon beams with pride, dabbing at her wet eyes.

Star rushes up the castle stairs, taking three steps at a time to expedite her journey. She reaches the top floor and nearly kicks down the tailor’s door, her breath catching in her throat when she sees Marco head to toe in his new royal suit. He smiles when he spots her, turning in a small circle to show off his whole outfit.

“It’s red,” Star gulps, her hands picking at her mouth nervously as her eyes flit around his form.

Marco’s brows fix together, “Is that a bad thing?”

She opens her mouth but words are lost to her. The tailor stands between them awkwardly, feeling stuffy from the tension, and quietly excuses himself from the room. Star’s jaw snaps shut with the thump of the door closing behind him.

“You’re perfect,” She finally murmurs, nearly choking on her own breath.

“Thank you,” he beams, “I thought red just felt right for me, ya know?”

Red _does_ feel right: the color of strength, of passion, of fire—the fire that tortures and teases her, that knocks the breath from her body and renders her useless in his presence. The fire she nearly forgot about until it reignites at the sight of his broad shoulders, trim waist, muscular arms wrapped in red like a Stump Day present.

“Marco,” she breathes his name, sending shivers down his spine, “If you’re really ready, I know where we can go— _for privacy,_ ” she clarifies.

He swallows hard, suddenly feeling claustrophobic in his clothes.

“I should change first,” he mentions, unable to form any other coherent sentences.

Star grabs his hand, forcing him to look at her, “Are you _really_ ready? I need you to tell me now.”

He scans her eyes, his mouth curling into a dopey grin as he leans in to kiss her, “I have never been more ready for anything.”

“100% positive?” She dodges his kiss, trying to keep him focused.

“I mean, I’d do it right now if you’d let me,” he half jokes, eliciting a bubble of a laugh from Star.

“Ok. Give me your scissors and go change,” she smirks, “I have the perfect spot in mind.”

When he returns, Star is standing in front of a portal, the blue light behind her creating a halo around her form. She holds her hand out and he takes it tentatively, his curiosity to where she is leading them piqued. They step through the portal and into a quiet dimension—it’s clearly dusk in this world, the lavender sky splaying up into an inky night overhead, the dark green grass spread out for miles, trees tall and shrouding them in shadow. He can hear the white-noise of bugs buzzing, but otherwise they seem to be completely alone.

“Where are we?” Marco hums, fascinated by the beautiful nature surrounding them.

“Glossaryk showed me this place whenever I would get overwhelmed. It’s become a meditation spot for me throughout the years. I’ve never showed anybody because I never wanted this place to be more than a secret between me and Glossaryk,” she pauses thoughtfully, “but I’m more than happy to share it with you.”

Marco looks around nervously, “So, uh, just right here, or...?”

“I—I think here is good,” Star’s voice is shaky, a drum of panic hammering in her ears. She tries to steady her breathing, pleading with her heart to quiet down. The last thing she wanted was one more interruption. She’s nervous, but more so excited. And ready. For real, she feels _ready_.

“Do you want me to just,” he stammers, playing aimlessly with the waist band of his jeans, “take these off?”

He’s awkward and stumbling over his own hands—hands she’s seen wield a sword skillfully dozens of times—and he’s mumbling and _god does she love this man_. She closes the gap between them, chastely pressing her lips to his. Marco swears he can feel her kiss down to his toes, his spine tingling and lower half twisting as he struggles to keep himself contained.

“I’m nervous, too,” Star backs out of the kiss, looking up at him, eyes dreamy and half lidded. Their relationship has always been based on emotional honesty, simple and stripped bare. Honesty and unwavering loyalty. And an abundance of physical intimacy.

Star takes the first step, her nimble fingers unfastening the button of her skirt, eyes still locked with her boyfriend. He follows her lead, undoing his own jeans and letting them fall to the ground. She steps out of her skirt as he kicks his jeans to the side, both then removing their own shirts. He thumbs around his boxers and Star encouragingly mirrors him, dropping the final pieces of fabric separating them from complete nakedness. They stand in front of one another, undressed, exposed, but this time there is no fear, no childish worries, only two adults ready to connect in new deeper ways.

Marco moves swiftly, scooping her into a panicked kiss, desperate and hot and he _can’t stand_ to not feel her skin on him any longer. She hikes her leg up around his hip and he lifts a hand under her bottom, dipping her as gently as possible to the ground. Shock locks up his joints when Star first _touches him_ , and he lets her guide him to her, their kiss muffling the groan vibrating from his throat when their bodies do connect. There’s resistance, a sharp inhale of breath, and then he’s frozen on top of her. She rocks into him encouragingly—pleading with him to move—finally inspiring his hips to thrust and hands to grab and grope greedily around her body, overwhelmed by the amount of skin available to explore. They move in tandem, pace quickening and bodies becoming one.

She continues to grind into him, releasing a ragged cry between hot kisses that goes straight to his groin, their intimacy not meant to last a long time. A few more bucks and groans against one another, and it’s all over as quickly as it began, the two left tangled together, toiling and sweating on the grass. Marco collapses his weight on her, burying his head in her shoulder as he pants, chest rising and falling against hers. She traces her finger tips along every vertebrae on his back, lovingly stroking him as he pulsates on top of her.

“S-sorry,” he huffs between breaths.

She laughs, pitchy and airy, pushing his shoulders up to make eye contact, “I love you so much, Marco.”

He puts his weight on one elbow, using his other hand to brush a few sweaty pieces of hair from her forehead, making room for his lips, “I love you, Star.”

She shifts on her side, curling into his chest as he envelopes her in his arms. He reaches a hand back to grab his red hoodie, using it as a makeshift blanket while they cuddle. The scene is euphoric, swaddled in Marco’s clothes and tangled in each other, both realizing this was worth the uncertainty, the emotions, the countless interruptions; this was worth the four years of building and tension and mutual pining. Together, they were ready to take on the world.

But for tonight, they simply took on adulthood.


End file.
